The overall objective of this project is to identify potent, selective, and bioactive small molecule modulators of TA systems for use as chemical probes. During this period, the team obtained purified stocks of all active compounds identified from the previously completed high-throughput screening campaign. These stocks were obtained by purchasing powders from commercial sources or in-house synthesis. The purified stocks were used to confirm in vitro activities and further evaluate using a variety of activity assays and biophysical methodologies. Assay development and optimization of additional target engagement assays were successfully completed.